Conveyors are used in industries for a number of purposes, and the present invention is particularly directed to a conveyor used for conveying objects where the objects may have elements or parts which extend outside the object itself, and which thereby may become stuck or entangled in the conveyor structure per se.
Such objects may be labels, handles, straps, etc. of luggage to be conveyed to and from for example the cargo bay in aircrafts, or be straps, strings or wires of products being conveyed in a manufacturing process.
The objects which have these elements extending from the object itself may be partly or wholly destroyed and further as the elements become stuck or entangled in the conveying structure, it may be necessary to shut down the entire conveying structure in order to liberate the element which has become stuck. In particular for luggage and the like, the luggage labels are very fragile, and may easily become detached from the piece of luggage. This may lead to problems relating to which destination to forward the luggage to, which aircraft it was meant for, who it belongs to, etc.
For industrial products, items are also sometimes labelled, in particular with test results for electronic equipment or quality control certificates, ingredient labelling, or weight/temperature characteristics. If this information is lost, the overall level of recognizability and determinability of the objects or produce used in the production process becomes unstable and unreliable.
From U.S. Pat. No. 2,307,389 a conveyor structure is known, wherein independent rollers are connected by means of plate members. The plate members of adjacent rollers overlap, and are provided with apertures, such that by superposing the apertures of two overlapping plate members and inserting a pin through the apertures, the two adjacent rollers may turn in relation to each other. At the extreme ends of the rollers, flange plates are provided, such that the flange plates on one roller will overlap the flange plates on an adjacent roller. The flange plates have a plane perpendicular to the transport plane created by the rollers. In this manner the flange plates help products/objects transported on the conveyor structure to stay on the rollers during turns.
In the art, a number of further conveying devices are constructed by interconnecting more or less self-propelling conveying elements such as for example disclosed in prior art patent applications US 2004 105740, U.S. Pat. Nos. 5,301,790, 5,584,376, 6,607,066, 2,494,302, FR 1564844, and EP 0767126. Common for all these prior art devices is the fact that they are constructed from interconnected and articulately connected conveying elements such that one conveying element may flex in relation to the adjacent conveying element. Furthermore, common for all these devices is the fact that as they are used in a side-flexing manner, there will be a varying gap between the conveying elements along the inner side of the curve in comparison to the outer side of the curve. It is, thereby, possible that parts of the objects to be conveyed along the conveying structure may become entangled in the conveying elements per se.
Furthermore, as this type of conveying structure is not provided with guiding elements along the extremities, it may have a tendency to twist in the plane such that one conveying element may be seriously out of the conveying plane due to the tensions arising in the system as the conveying structure is made to side-flex. This is partly due to the fact that the conveying elements extend to both sides of a centrally arranged connection system, which connection system may be constructed such that it is highly articulate, i.e. it will be fairly easy to angle one conveying element in relation to the adjacent conveying element. Even on a smooth surface, the tension in the system may create twisting, and thereby a scissor-like configuration of the conveying elements making up the conveying structure.